Does anyone know what the spring rates are on the Rubicon?

[smlobx]

As the title says I’m looking into possibly upgrading the springs on my JTR, particularly in the rear once my build is completed. So if you happen to have access to that info I’d appreciate you passing along the info..

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[KurtP]

As the title says I’m looking into possibly upgrading the springs on my JTR, particularly in the rear once my build is completed. So if you happen to have access to that info I’d appreciate you passing along the info..

roughly 180lb/in on the rear and 135lb/in on the front; measured at 1000lb

 

[smlobx]

roughly 180lb/in on the rear and 135lb/in on the front; measured at 1000lb

That seems a little light.. I would have thought they would be in the 250 to 300 pound range..
Do you have any documentation you could point me to?

 

[21RG]

Is there a difference with the diesel springs?

 

[kevman65]

https://www.jeepgladiatorforum.com/forum/threads/rubicon-spring-rates-measured.29558/

He tested them himself. He gives the part numbers he has. Not a complete test.

 

[KurtP]

Is there a difference with the diesel springs?

Diesel front springs are stiffer

 

[KurtP]

That seems a little light.. I would have thought they would be in the 250 to 300 pound range..
Do you have any documentation you could point me to?

Nah. They arent stiff at all.

The clayton triple rates have 190 at the first stage to ish-match stock with bumper, 280 at the second stage for load, and 360 third for final load/bottom out.

There is a thread somewhere here where a guy put the springs in a press and measured the rates at 1,000lb. They are pretty close to the jlu rates. There’s not a lot of spring in the trucks.

Do you want lift from the spring? Or just more load?

 

[smlobx]

Thanks everyone for chiming in. I’ve learned a lot from this thread and the ones linked.

My knowledge of spring rates come from my days racing Porsche’s where one of our builds we took a stock Porsche with 250/300 springs and eventually we’re running 650/750 springs on a car that was over 600 pounds lighter than stock. But boy could that car fly through the corners!

I know that spring use in Jeep’s is different that race cars but I didn’t realize how soft the springs really were in a truck that is designed to carry a certain amount of weight. Another thing I didn’t realize, if I’m understanding correctly, is that Jeep’s use different spring rates from one side of an axle to the other...that’s actually high grade engineering right there..!!

It is also interesting to see that the 2” Mopar lift has a higher spring rate. This might be the way I go after I finish my build and weigh each corner to try and determine the best spring rate.

 

[kevman65]

Synergy will give you specific information on their springs, you just can't buy direct from them and their resellers don't carry all of the springs

Since you've raced in the past, you already have places to start, just need to give them the dimensions and weights you want.

 

[KurtP]

Thanks everyone for chiming in. I’ve learned a lot from this thread and the ones linked.

My knowledge of spring rates come from my days racing Porsche’s where one of our builds we took a stock Porsche with 250/300 springs and eventually we’re running 650/750 springs on a car that was over 600 pounds lighter than stock. But boy could that car fly through the corners!

I know that spring use in Jeep’s is different that race cars but I didn’t realize how soft the springs really were in a truck that is designed to carry a certain amount of weight. Another thing I didn’t realize, if I’m understanding correctly, is that Jeep’s use different spring rates from one side of an axle to the other...that’s actually high grade engineering right there..!!

It is also interesting to see that the 2” Mopar lift has a higher spring rate. This might be the way I go after I finish my build and weigh each corner to try and determine the best spring rate.

The spring rates on race cars are incredibly stiff. The rates are different left to right as is the free length of the spring.

You could also have Eibach wind a spring to your specifications if you so choose. If you end up finding data that is better than what we currently have available, please let us know!

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